There's only two ways a wheel cylinder can blow apart. One is if it physically turned. That is a huge GM problem with clipped-on wheel cylinders on their rear-wheel-drive cars. There is an updated backing plate for that problem. The other way would involve a combination of worn linings, shoes not adjusted up, and a drum that is worn or was machined well over the published legal limit. A sticking parking brake cable can prevent the automatic adjuster from doing its job but you will also typically have a lower than normal pedal. Also check for grooves worn in the six "lands" on the backing plate that the shoes ride on. They should be lubed with high-temperature brake grease when the shoes are replaced. If those grooves are deep enough, they can prevent the shoes from applying or releasing properly. Often you will feel the brake pedal suddenly drop just a little when a caught shoe pops over the grooves. Shoes catching on the grooves will also adversely affect the automatic adjusting.
Wednesday, August 25th, 2010 AT 2:17 PM